Systems

Do they matter? What is a system anyway?

• A group of interacting, interrelated, or interdependent elements forming a complex whole, especially.

• An organism as a whole, especially with regard to its vital processes or functions.

• A group of physiologically or anatomically related organs or parts.

In fact, systems are everywhere. You are one. Where we live is one.  Your phone is one.  Many things we see each day are in fact systems. A car, a clock, a power plant, a farm, a stream... many different types of systems. 

General Systems theory

Ludwig von Bertalanffy (1901-1972)​

• Systems Theory: the trans-disciplinary study of the abstract organisation of phenomena, independent of factors (substance, type, location etc.) ​

• It examines both the principles common to all complex entities, and the (usually mathematical) models which can be used to describe them.​

• We all work within and between a variety of systems: structural systems (a road network), functional systems (academic department), social system (work group), information system (a class or course).

• A system is more than the sum of it's parts; it's properties emerge from the relationship among it's parts and from the system's relationship to its environment​

• Systems are arranged hierarchically, so every system is a super system for systems contained within it and a subsystem for systems containing it​.  Does this remind you of Classes? How?

Types of systems

• Systems differ from each other in relation to their degree of self-sufficiency, complexity, and adaptability.​

• Closed systems have fixed relationships among system components and no interaction with the environment. 

• Open systems interact with their environment, have dynamic interaction of components, and can be self-regulating.​

• Human organisations are open systems; boundaries are permeable, continually engage in importing, transforming, and exporting matter, energy, information, and people; Human organisations are at the high end of the complexity scale due to these characteristics.​

Properties

• A system must maintain balance or homeostasis if it is to survive. ​

• In order to avoid entropy (chaos) the system must engage in regulation and control as well as the management of its position in the super-system.  Stable systems have a form of feedback loop to maintain balance.

Equifinality is the principle by which a system can get to the same end (or goal) from various different routes. That is the same inputs can result in the same outputs by different processes. ​

• If you (as a subsystem) are required to obtain a book via input from the environment (the boss has asked you to get a book) you may come to the next meeting with the book (output). ​

• You may have picked it up at the bookshop or the library but the result is the same. 

The boundary of a system consists of features which define and delineate the system​

• • System boundary in a use-case diagram​

The environment is everything that does not belong to the system, yet still interacts with the system​

• • Actors​ in a use-case diagram

The system is inside the boundary and the environment is outside the boundary​

How might closed/open systems influence:

• Interdependence:  a change in one part of the system will result in a change in another part of the system (propagation of change). ​

• Independence: where a particular part of the system has some responsibility for some functionally related activity. ​

Ideally system components should be independent with respect  to each other, while being highly interdependent internally. (a loose coupling of highly cohesive elements).  Think about an application created using a set of five or six modules- each module can work just fine on it's own, but when combined into an application, the removal of any one module might cause the entire app to fail.

Nonsummativity (noun) 

refers to a quality or characteristic of a system where the whole is not equal to the sum of its parts. It reflects a situation in which the individual components of a system interact in such a way that their combined effect is different from, or greater than, the mere addition of their individual effects. “The whole is greater than the sum of its parts” – a phrase often used to embody the concept of nonsummativity in different contexts.

Core Meaning: The fundamental concept that the properties or behaviors of a whole cannot be fully understood just by examining its parts separately.

Extended Meaning: It can also imply that the interactions or relationships within a system create emergent properties—characteristics that are only observable when the components are combined.

Example: “The nonsummativity of our team’s efforts resulted in a project outcome that was far beyond what any single member could have achieved alone.”

You can find a complete timeline of the development of modern information systems here.

Hierarchies

All systems naturally tend towards a hierarchy.  A hierarchy is an arrangement of items in which the items are represented as being "above", "below", or "at the same level as" one another. Hierarchy is an important concept in a wide variety of fields, such as philosophy, mathematics, computer science, organisational theory, systems theory, systematic biology, and the social sciences

You can also see the concept of systems with sub-systems here in human biology, just as computers are made of many sub-systems.  Large software systems such as telephony networks are comprised of many thousands of modules and sub modules.  Other hierarchies do not have that feature, such as Maslows hierarchy of needs- but in order to reach the higher levels of the hierarchy, the lower needs must be met.